Java Runtime Environment is a secure computing environment which gives you the ability to run Java based applications. Java allows you to play games, communicate with people, calculate mortgage interest, view images in 3D, and make use of a limitless variety of other applications.

The Java Runtime Environment is required to use the features of Java and to make use of software that is built around this powerful system. Also referred to as the Java Runtime, Runtime Environment, Runtime, JRE, Java Virtual Machine, Virtual Machine, Java VM, JVM, VM, Java plug-in, Java plugin, or Java add-on.

The JRE is the runtime element of Java software, which is the only thing you need to run Java in your web browser.